The active matrix organic light emitting diode (AMOLED) display technology is a display technology applied in televisions and mobile devices, which has broad application prospects in portable electronic devices that are sensitive to power consumption by right of its characteristics of low power consumption, low cost and large size.
The organic light emitting diode (OLED) in the AMOLED can emit light because it is driven by the driving current generated by thin film transistors (TFTs). However, the threshold voltage of the TFT might change over time, which results in the problem that with the same inputted voltage on the TFTs, the driving currents generated by the TFTs are inconsistent, so as to cause the brightness of respective OLEDs to be different and the brightness of the AMOLED consisting of a plurality of OLEDs to be nonuniform, thereby influencing the display effect of the whole image.